Old Campag BB - spindle not centred?

[cycletothesea]

Hi,

Noticed recently that my double chain-rings on my Shorter road bike were remarkably close to the chain stay (probably less than a couple of mm). So I took off the cranks to look possible replacing the bottom bracket for a longer one. However, I noticed that the spindle on the present one, 68mm/115mm size, is off centre, which I'm not sure can be right - can it?

I think the BB size is probably correct for a double-chain ring. Is it possible to re-centre the spindle within the BB, which would sort the problem, or is it meant to be like this?

You can see from the pics, just about, that it's not central.

 

[Excel]

presuming you are using a Campag B/B axle and chainset then this useful link could answer your query....<< http://www.minortriad.com/campagbb.html >>

 

[Midlife]

The BB axle is asymmetrical and more sticks out the drive side. It the rings clear the chain stay what is the problem?

Shaun

 

[cycletothesea]

Okay, that's fine then. Thanks. Just seems like there should be a tad more than 1mm clearance between crank and chainstay. But will leave it be I guess.

Thanks
P.

 

[originalshinkicker]

It is possible, over time, for the square in the alloy crank arm to become stretched (or from over tightening). 1mm is ok but is tight. If you have enough thread on the adjustable cup, you can fit a spacer behind the fixed cup to space the chainset out. Something like this ...

http://www.starcyclespares.co.uk/bike-f ... 2854-p.asp

 

[Midlife]

Asymmetric campag axles were 112mm for pre 1978 chainsets and 114mm for post 1978 chainsets IIRC so I guess you have the longer one anyway.

Short wheelbase frames were always tight as the chainstay angle increases, add in the trend for only a small "dent" in the chainstay where the rings are and that's a recipe for the rings to be close to the chainstay.

As originalshinkicker says you can add a spacer or just keep an eye on it.

My short wheelbase 1970's TT bike won't take an inner chainring at all on a campag double axle !!

Shaun

 

[Old Ned]

Are the cups a pair? Campag made both thin-wall and thick-wall versions at different periods.